Luna

Luna is the natural satellite of the planet Terr. It is estimated to be roughly 1/7 the size of Terr. It orbits Terr every 30 days, which is the origin of the calendar most typically used.

Luna has its own natural satellite, Paradis. Paradis orbits Luna fairly quickly and can be seen by the naked eye from the surface of Terr. It is used to mark the passage of time at night. If it can be seen, it takes 4 hours for Paradis to cross the face of Luna, and 6 hours to either fully come around to the face, or 6 hours to disappear behind Luna again. Total orbit time is only 20 hours, so one cannot tell what time it is at the moment, only how much time has passed (unless they have an Luna/Paradis orbital calendar handy).

Both Luna and Paradis are considered of great importance for many religions on Terr, from the location of heaven, to the paradise of the gods to the gods themselves, Luna and Paradis are universally revered for a multitude of reasons.